www.pudn.com > SerialGPS.zip > Constants.m

function Constants 
% This M-file defines global constants for the numeric values in 
% the GPS communication protocols. These values have been tested with 
% Garmin brand GPS systems (specifically, the eTrex Venture). 
 
% Basic Packet Identifiers 
global pid_etx_byte pid_ack_byte pid_dle_byte pid_nak_byte 
global pid_protocol_array pid_product_rqst pid_product_data 
 
pid_etx_byte = 3;    % ASCII ETX (End of text) 
pid_ack_byte = 6;    % ASCII ACK (Acknowledge) 
pid_dle_byte = 16;   % ASCII DLE (Data link escape) 
pid_nak_byte = 21;   % ASCII NAK (Not acknowledge) 
pid_protocol_array = 253; 
pid_product_rqst = 254; 
pid_product_data = 255; 
 
% Link Protocol 1 
global pid_command_data pid_xfer_cmplt pid_date_time_data pid_position_data 
global pid_prx_wpt_data pid_records pid_rte_hdr pid_rte_wpt_data  
global pid_almanac_data pid_trk_data pid_wpt_data pid_pvt_data  
global pid_rte_link_data pid_trk_hdr 
 
pid_command_data    = 10; 
pid_xfer_cmplt      = 12; 
pid_date_time_data  = 14; 
pid_position_data   = 17; 
pid_prx_wpt_data    = 19; 
pid_records         = 27; 
pid_rte_hdr         = 29;    
pid_rte_wpt_data    = 30; 
pid_almanac_data    = 31; 
pid_trk_data        = 34; 
pid_wpt_data        = 35; 
pid_pvt_data        = 51; 
pid_rte_link_data   = 98; 
pid_trk_hdr         = 99; 
 
% Device Command Protocol 1 (A010) 
global cmd_abort_transfer cmd_transfer_alm cmd_transfer_posn cmd_transfer_prx 
global cmd_transfer_rte cmd_transfer_time cmd_transfer_trk cmd_transfer_wpt 
global cmd_turn_off_pwr cmd_start_pvt_data cmd_stop_pvt_data 
 
cmd_abort_transfer  = 0; 
cmd_transfer_alm    = 1;    % Almanac 
cmd_transfer_posn   = 2;    % Position 
cmd_transfer_prx    = 3;    % Proximity waypoints 
cmd_transfer_rte    = 4;    % Routes 
cmd_transfer_time   = 5;    % Current time 
cmd_transfer_trk    = 6;    % Track log 
cmd_transfer_wpt    = 7;    % Waypoints 
cmd_turn_off_pwr    = 8;    % Turn off device power 
cmd_start_pvt_data  = 49;   % Begin transfer of PVT data 
cmd_stop_pvt_data   = 50;   % End transfer of PVT data